International Air Transport Association airport code

An IATA airport code, also known an IATA location identifier, IATA station code or simply a location identifier,[1] is a three-letter code designating many airports around the world, defined by the International Air Transport Association (IATA). The characters prominently displayed on baggage tags attached at airport check-in desks are an example of a way these codes are used.

The assignment of these codes is governed by IATA Resolution 763, and it is administered by IATA headquarters in Montreal. The codes are published biannually in the IATA Airline Coding Directory.[2]

Airport codes arose out of the convenience that it brought pilots for location identification in the 1930s. Initially, pilots in the United States used the two-letter code from the National Weather Service (NWS) for identifying cities. This system became unmanageable for cities and towns without an NWS identifier, thus a three-letter system of airport codes was implemented. This system allowed for 17,576 permutations, assuming all letters can be used in conjunction with each other.[3]

Large metropolitan areas with more than one airport often resort to codes named after the airport itself instead of the city it serves. Often, another code is reserved which refers to the city itself. For instance:

IATA codes should not be confused with the FAA identifiers of US airports. Most FAA identifiers agree with the corresponding IATA codes, but some do not, such as Saipan whose FAA identifier is GSN and its IATA code SPN, and some coincide with IATA codes of non-US airports.

Many cities retain historical names in their airport codes despite the fact that their official name is now different. This is especially prominent in India: BOM for Mumbai (formerly Bombay), CCU for Kolkata (formerly Calcutta), and MAA for Chennai (formerly Madras); in China: CAN for Guangzhou (formerly Canton), PEK for Beijing (formerly Peking), and TAO for Qingdao (formerly Tsingtao). Similarly, this is the case with FRU for Bishkek (formerly Frunze), LED for St. Petersburg (formerly Leningrad), GOJ for Nizhny Novgorod (formerly Gorky), SGN for Ho Chi Minh City (formerly Saigon), and TGD for Podgorica (formerly Titograd).

Some airport codes are based on previous names associated with a present airport, such as Chicago's O'Hare, which is assigned ORD, based on its old name of Orchard Field, before it was expanded and renamed O'Hare in the mid-1950s. Similarly, Orlando International Airport uses MCO, based on the old McCoy Air Force Base, which was converted to joint civilian/military use and renamed Orlando Jetport at McCoy in the early 1960s and finally Orlando International in the early 1980s. Other airport codes are similarly not immediately obvious in origin, and each have their own peculiarities. Nashville uses BNA, Knoxville uses TYS, and Kahului (the main gateway into Maui) uses OGG, while Spokane International Airport goes by GEG. Most of these are named after individuals.[3] In Asia, codes that do not correspond with their city's names include Niigata's KIJ, Nanchang's KHN, Zhengzhou's CGO, Pyongyang's FNJ, and Kobe's UKB.

Some airports are identified even in colloquial speech by their airport code. The most notable example is LAX.

All major airports in Canada use airport codes that begin with the letter "Y", although not all "Y" codes are Canadian. Many Canadian airports simply append a combinations of letters in the city's name to the "Y": YOW for Ottawa, YYC for Calgary, and YVR for Vancouver, whereas other Canadian airports simply use the arbitrary letters assigned to them, such as YQX in Gander and YXS in Prince George. While certain codes themselves make it more difficult to identify an airport, some codes have become popular in usage due to the airports, particularly two of Canada's largest airports, YYZ for Toronto-Pearson and YUL for Montreal-Trudeau. Canada's third busiest airport, Calgary International Airport,[4] has begun using its airport code YYC as a marketing brand and name for the airport authority web site (yyc.com). [5]

Numerous New Zealand airports use codes which contain a letter Z, to distinguish them from similar airport names in other countries. Examples include HLZ for Hamilton, ZQN for Queenstown, and WSZ for Westport.